Luxembourg City, Luxembourg (SportsNetwork.com) - Top seeds Caroline Wozniacki and Sloane Stephens were winners Tuesday in the first round of the Luxembourg Open.

The top-seeded Wozniacki battled past crowd favorite Mandy Minella of Luxembourg with a 6-3, 7-6 (7-2) triumph, while the second-seeded Stephens had an easier time against Swiss wild card Timea Bacsinszky, 6-3, 6-3.

Wozniacki, the 2008 Luxembourg runner-up, hasn't won a tournament in a year. The former world No. 1 captured the last of her 20 career titles this week last year in Moscow, a tournament that is being played simultaneously. Her best finish this year was a loss to Maria Sharapova in the Indian Wells final back in March.

Stephens is having a strong season despite not having won a tournament. The 20-year-old American reached the semifinals of the Australian Open after surprising Serena Williams in the quarters, reached the quarterfinals at Wimbledon and fell in the fourth round at both the French and U.S. Opens.

Next up for Stephens will be Austrian veteran Yvonne Meusburger, a 6-4, 6-2 winner over Romania's Irina-Camelia Begu.

Third-seeded Sabine Lisicki overcame a sluggish start to defeat Croatia's Donna Vekic, 2-6, 6-3, 6-0 and will take on the winner of Wednesday's first- round match between Kristina Mladenovic of France and Czech Tereza Smitkova.

Polish qualifier Katarzyna Piter knocked off fourth-seeded Kirsten Flipkens of Belgium, 6-4, 6-2, and will next square off against another Belgian, Yanina Wickmayer, in the second round. Wickmayer advanced Monday.

Also Tuesday, Switzerland's Stefanie Voegele pulled off a 1-6, 6-4, 7-6 (7-3) upset of sixth-seeded German Mona Barthel and will next meet the Czech Republic's Karolina Pliskova, a 5-7, 7-5, 6-1 winner over Spain's Lourdes Dominguez Lino.

Taiwan's Su-Wei Hsieh rallied for a 4-6, 7-6 (7-2), 6-3 victory over Slovakian qualifier Kristina Kucova and Italy's Karin Knapp rallied for a 4-6, 6-3, 6-3 triumph over qualifier Sesil Karatantcheva.

The 2013 Luxembourg champion will take home $44,000.